<template>
  <div class="goods-sku">
    <dl v-for="item in goods.specs" :key="item.id">
      <dt>{{item.name}}</dt>
      <dd>
        <template v-for="val in item.specValue" :key="val.id">
          <img :class="{ selected: val.selected, disabled: val.disabled }" @click="clickSpecs(item, val)"
               v-if="val.picture" :src="val.picture" />
          <span :class="{ selected: val.selected, disabled: val.disabled }" @click="clickSpecs(item, val)" v-else>
            {{val.name}}</span>
        </template>
      </dd>
    </dl>
  </div>
</template>

<script setup lang="ts">
import { watchEffect, reactive, toRefs, onMounted, watch, type PropType } from 'vue'
import getPowerSet from './power-set.ts'

const spliter = '★'
const emits = defineEmits(['change'])
const props = defineProps({
  goods: {
    type: Object as PropType<{ specs: any[]; skus: any[] }>,
    default: () => ({ specs: [], skus: [] })
  }
})


// 根据 skus 数据得到路径字典对象
const getPathMap = (goodsSkus: any[]): Record<string, number[]> => {
  const pathMap: Record<string, number[]> = {}
  if (goodsSkus && goodsSkus.length > 0) {
    goodsSkus.forEach(sku => {
      // 1. 过滤出有库存有效的 sku
      if (sku.inventory) {
        // 2. 得到 sku 属性值数组
        const specs = sku.specs.map(spec => specs.name)
        // 3. 得到 sku 属性值数组的子集
        const powerSet = getPowerSet(specs)
        // 4. 设置给路径字典对象
        powerSet.forEach(set => {
          const key = set.join(spliter)
          // 如果没有就先初始化一个空数组
          if (!pathMap[key]) {
            pathMap[key] = []
          }
          pathMap[key].push(sku.id)
        })
      }
    })
  }
  return pathMap
}

// 初始化禁用状态
function initDisabledStatus(specs: any[], pathMap: Record<string, number[]>): void {
  if (specs && specs.length > 0) {
    specs.forEach(spec => {
      spec.specValue.forEach(val => {
        // 设置禁用状态
        val.disabled =!pathMap[val.name]
      })
    })
  }
}

// 得到当前选中规格集合
const getSelectedArr = (specs: any[]): string[] => {
  const selectedArr: string[] = []
  specs.forEach((spec, index) => {
    const selectedVal = spec.specValue.find(val => val.selected)
    if (selectedVal) {
      selectedArr[index] = selectedVal.name
    } else {
      selectedArr[index] = undefined
    }
  })
  return selectedArr
}

// 更新按钮的禁用状态
const updateDisabledStatus = (specs: any[], pathMap: Record<string, number[]>): void => {
  // 遍历每一种规格
  specs.forEach((item, i) => {
    // 拿到当前选择的项目
    const selectedArr = getSelectedArr(specs)
    // 遍历每一个按钮
    item.values.forEach(val => {
      if (!val.selected) {
        selectedArr[i] = val.name
        // 去掉 undefined 之后组合成 key
        const key = selectedArr.filter(value => value).join(spliter)
        val.disabled =!pathMap[key]
      }
    })
  })
}

let pathMap: Record<string, number[]> = {}

watchEffect(() => {
  // 得到所有字典集合
  pathMap = getPathMap(props.goods.skus)
  // 组件初始化的时候更新禁用状态
  initDisabledStatus(props.goods.specs, pathMap)
})

const clickSpecs = (item: any, val: any) => {
  if (val.disabled) return false
  // 选中与取消选中逻辑
  if (val.selected) {
    val.selected = false
  } else {
    item.values.forEach(bv => {
      bv.selected = false
    })
    val.selected = true
  }
  // 点击之后再次更新选中状态
  updateDisabledStatus(props.goods.specs, pathMap)
  // 把选择的 sku 信息传出去给父组件
  // 触发 change 事件将 sku 数据传递出去
  const selectedArr = getSelectedArr(props.goods.specs).filter(value => value)
  // 如果选中得规格数量和传入得规格总数相等则传出完整信息(都选择了)
  // 否则传出空对象
  if (selectedArr.length === props.goods.specs.length) {
    // 从路径字典中得到 skuId
    const skuId = pathMap[selectedArr.join(spliter)][0]
    const sku = props.goods.skus.find(sku => sku.id === skuId)
    // 传递数据给父组件
    if (sku && sku.specs) {
      emits('change', {
        skuId: sku.id,
        price: sku.price,
        oldPrice: sku.oldPrice,
        inventory: sku.inventory,
        specsText: sku.specs.reduce((p, n) => `${p} ${n.name}:${n.valueName}`, '').trim()
      })
    }
  } else {
    emits('change', {})
  }
}
</script>

<style scoped lang="scss">
@mixin sku-state-mixin {
  border: 1px solid #e4e4e4;
  margin-right: 10px;
  cursor: pointer;

  &.selected {
    border-color: $xtxColor;
  }

  &.disabled {
    opacity: 0.6;
    border-style: dashed;
    cursor: not-allowed;
  }
}

.goods-sku {
  margin-top: -5px;
  padding-left: 10px;
  padding-top: 5px;

  dl {
    display: flex;
    padding-bottom: 20px;
    align-items: center;

    dt {
      width: 50px;
      color: #999;
    }

    dd {
      flex: 1;
      color: #666;

      > img {
        width: 50px;
        height: 50px;
        margin-bottom: 4px;
        @include sku-state-mixin;
      }

      > span {
        display: inline-block;
        height: 30px;
        line-height: 28px;
        padding: 0 20px;
        margin-bottom: 4px;
        @include sku-state-mixin;
      }
    }
  }
}
</style>